Buggy code:
public abstract class ReferenceBinding extends TypeBinding implements IDependent { public char [ ] [ ] compoundName ; public char [ ] sourceName ; public int modifiers ; public PackageBinding fPackage ; char [ ] fileName ; char [ ] constantPoolName ; char [ ] signature ; public FieldBinding [ ] availableFields ( ) { } public MethodBinding [ ] availableMethods ( ) { } public boolean canBeInstantiated ( ) { } public final boolean canBeSeenBy ( PackageBinding invocationPackage ) { } public final boolean canBeSeenBy ( ReferenceBinding receiverType , SourceTypeBinding invocationType ) { } public final boolean canBeSeenBy ( Scope scope ) { } public void computeId ( ) { } public char [ ] constantPoolName ( ) { } public String debugName ( ) { } public final int depth ( ) { } public ReferenceBinding enclosingType ( ) { } public final ReferenceBinding enclosingTypeAt ( int relativeDepth ) { } public int fieldCount ( ) { } public FieldBinding [ ] fields ( ) { } public ReferenceBinding findSuperTypeErasingTo ( int erasureId , boolean erasureIsClass ) { } public ReferenceBinding findSuperTypeErasingTo ( ReferenceBinding erasure ) { } public final int getAccessFlags ( ) { } public MethodBinding getExactConstructor ( TypeBinding [ ] argumentTypes ) { } public MethodBinding getExactMethod ( char [ ] selector , TypeBinding [ ] argumentTypes ) { } public MethodBinding getExactMethod ( char [ ] selector , TypeBinding [ ] argumentTypes , CompilationUnitScope refScope ) { } public FieldBinding getField ( char [ ] fieldName , boolean needResolve ) { } public char [ ] getFileName ( ) { } public ReferenceBinding getMemberType ( char [ ] typeName ) { } public MethodBinding [ ] getMethods ( char [ ] selector ) { } public PackageBinding getPackage ( ) { } public boolean hasMemberTypes ( ) { } public TypeVariableBinding getTypeVariable ( char [ ] variableName ) { } public int hashCode ( ) { } public final boolean hasRestrictedAccess ( ) { } public boolean implementsInterface ( ReferenceBinding anInterface , boolean searchHierarchy ) { } boolean implementsMethod ( MethodBinding method ) { } public final boolean isAbstract ( ) { } public final boolean isAnonymousType ( ) { } public final boolean isBinaryBinding ( ) { } public boolean isClass ( ) { } public boolean isHierarchyBeingConnected ( ) { } public boolean isCompatibleWith ( TypeBinding otherType ) { } public final boolean isDefault ( ) { } public final boolean isDeprecated ( ) { } public final boolean isFinal ( ) { } public boolean isInterface ( ) { } public final boolean isPrivate ( ) { } public final boolean isPrivateUsed ( ) { } public final boolean isProtected ( ) { } public final boolean isPublic ( ) { } public final boolean isStatic ( ) { } public final boolean isStrictfp ( ) { } public boolean isSuperclassOf ( ReferenceBinding otherType ) { while ( ( otherType = otherType . superclass ( ) ) != null ) { <START_BUG> if ( this . isEquivalentTo ( otherType ) ) <END_BUG> return true ; } return false ; } public final boolean isViewedAsDeprecated ( ) { } public ReferenceBinding [ ] memberTypes ( ) { } public MethodBinding [ ] methods ( ) { } public char [ ] qualifiedSourceName ( ) { } public char [ ] readableName ( ) { } public char [ ] shortReadableName ( ) { } public char [ ] signature ( ) { } public char [ ] sourceName ( ) { } public ReferenceBinding superclass ( ) { } public ReferenceBinding [ ] superInterfaces ( ) { } public ReferenceBinding [ ] syntheticEnclosingInstanceTypes ( ) { } public SyntheticArgumentBinding [ ] syntheticOuterLocalVariables ( ) { } MethodBinding [ ] unResolvedMethods ( ) { } }

Fix:
if ( otherType . isEquivalentTo ( this ) )